Effects of the insecticides DDT and dieldrin on phosphorus metabolism of the adult housefly Musca domestica L.

Abstract

A PROTEOLYTIC ENZYME FROM RABBIT SPLEEN 543 amount of products which are not precipitable by trichloroacetic acid. 2. The enzyme responsible for this proteolytic activity has been purified by adsorption of inactive material on diethylaminoethylcellulose and carboxymethylcellulose. 3. Chromatography on diethylaminoethylcellulose has demonstrated the existence of only one enzyme in the purified preparation. 4. The optimum pH and the Michaelis constant of this enzyme are the same as those of the proteolytic activity in the crude preparation. It was therefore concluded that this enzyme is responsible for the proteolytic activity of the crude spleen extracts. 5. A comparative study of the immunoelectrophoresis patterns given by human-serum albumin, degraded with the crude and purified spleen extracts, has shown that it is this enzyme which is responsible in both cases for the splitting of the antigenic structure of human-serum albumin. We wish to thank Dr P. Grabar for his advice and Mrs J. Cavillon for her technical assistance. One of us (C.L.) aoknowledges the support of the Institut National d'Hygiene, Paris. This work was done while T.W. was a post-doctoral research fellow of the Life Insurance Medical Rewearch Fund.

Effects of DDT on oxygen consumption of Rhodnius prolixus Stål

“…These suggestions are unsatisfactory to the extent that they imply that prostration is essentially irreversible, each step being terminated when the next is triggered. This may be true of stress prostration (Beament, 1958;Heslop & Eay, 1959), but in the early stages DDT prostration is essentially reversible; it is well known that house-flies in the prostrate stage of DDT poisoning will recover if the temperature is raised sufficiently (Sacktor, 1952;Eoth, Lindquist & Terriere, 1953;Keiding, 1954) and that partial recovery may occur if they are injected with glucose solution (Winteringham, Hellyer & McKay, 1960). Further, DDTpoisoned fed fifth-instar larvae of Rhodnius may be fully prostrate for up to 40 days and yet recover (Spiller, 1955).…”